1. Field of the Invention
The present invention relates to an electronic pedometer which has an acceleration sensor as a walk sensor, and which is attached to an arm of a user by a band.
2. Description of the Prior Art
An electronic pedometer disclosed in JP-A-2005-309693 has an acceleration sensor as a walk sensor outputting a walk signal corresponding to a walk by detecting the walk of a user, a step number calculation means calculating a step number of the user on the basis of the walk signal, and a belt for attaching the acceleration sensor to a wrist of the user. The acceleration sensor is disposed in an electronic pedometer case such that its sensitivity shaft is located in a predetermined angle range with respect to a longitudinal direction of the belt. The “predetermined angle range” means that the sensitivity shaft of the acceleration sensor exists in a range from 90 degrees to less than 30 degrees counterclockwise with respect to the longitudinal direction of the belt, or a range from 90 degrees to less than 30 degrees clockwise with respect to the longitudinal direction of the belt.
The above conventional electronic pedometer has such an advantage that also a walk, performed without swinging the arm can be detected needless to say about a case where the user normally walks or runs.
However, not limited to the above conventional electronic pedometer, the electronic pedometer having the acceleration sensor as the walk sensor has a problem that a false step number is counted in a case where the user has moved only the arm without walking. Such a case is a case where the user is engaged in desk work such as personal computer work, a case where the user turns a page of a book, or the like.
That is, in the case where the user, who has worn the electronic pedometer having possessed the acceleration sensor, is engaged in a desk work such as personal computer work, the acceleration sensor detects a vibration of the wrist and outputs an acceleration signal. Whereupon, it follows that the electronic pedometer counts the acceleration signal as the step number. In other words, in the electronic pedometer having possessed the acceleration sensor, there is a problem that, if the electronic pedometer outputs the acceleration signal also by a motion of the user other than the walk, the step number is counted, so that the step number larger than a real step number is recorded and displayed.
A problem that the invention is to solve is to make such that, in the electronic pedometer having possessed the acceleration sensor, the acceleration signal having been generated by the motion of the user other than the walk is not counted as the step number.